From: Nikita Popov <nikita.ppv@gmail.com>
Date: Tue, 28 Jan 2020 10:23:16 +0000 (+0100)
Subject: Perform map ptr base arithmetic through uintptr_t
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c59219de85a82548e7ba12399b95eae9087b3dfd;p=php

Perform map ptr base arithmetic through uintptr_t

Adding an offset to the NULL pointer is undefined behavior.
Avoid this by performing arithmetic on uintptr_t instead.
---

diff --git a/Zend/zend_map_ptr.h b/Zend/zend_map_ptr.h
index 46596b5c37..c6930473cf 100644
--- a/Zend/zend_map_ptr.h
+++ b/Zend/zend_map_ptr.h
@@ -80,9 +80,9 @@
 		ZEND_MAP_PTR(ptr) = zend_map_ptr_new(); \
 	} while (0)
 # define ZEND_MAP_PTR_REAL_BASE(base) \
-	((void*)(((char*)(base)) + 1))
+	((void*)(((uintptr_t)(base)) + 1))
 # define ZEND_MAP_PTR_SET_REAL_BASE(base, ptr) do { \
-		base = (void*)(((char*)(ptr)) - 1); \
+		base = (void*)(((uintptr_t)(ptr)) - 1); \
 	} while (0)
 #else
 # error "Unknown ZEND_MAP_PTR_KIND"